GaAlN/GaN HEMT heterostructures grown on SiCopSiC composite substrates for HEMT application

• Published in: Journal of crystal growth 2008-11, Vol.310 (23), p.5232-5236
• Main Authors: di Forte Poisson, M.-A., Magis, M., Tordjman, M., Di Persio, J., Langer, R., Toth, L., Pecz, B., Guziewicz, M., Thorpe, J., Aubry, R., Morvan, E., Sarazin, N., Gaquière, C., Meneghesso, G., Hoel, V., Jacquet, J.-C., Delage, S.
• Format: Article
• Language: English
• Subjects: A1. Defects; A3. Metalorganic vapour phase epitaxy; Applied sciences; B1. Nitrides; B2. Semiconducting III–V materials; B3. Field effect transistors; B3. Heterojunction semiconductor devices; B3. High electron mobility transistors; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Cross-disciplinary physics: materials science; rheology; Electronics; Engineering Sciences; Exact sciences and technology; Materials science; Methods of crystal growth; physics of crystal growth; Methods of deposition of films and coatings; film growth and epitaxy; Other materials; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Specific materials; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; Transistors
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2008.08.035

This paper reports on low-pressure metalorganic vapour deposition (LP-MOCVD) growth optimisation of GaAlN/GaN heterostructures grown on SiCopSiC (silicon carbide-oxyde-polycrystalline silicon carbide) composite substrates for HEMT applications, and on the first device performances obtained with these structures. Some critical growth parameters, such as growth temperature, V/III ratio and nucleation layer at the GaN/SiC interface, have been investigated, and their impact on physical properties of these heterostructures is studied. Such optimisation of the growth conditions has led to GaAlN/GaN HEMT heterostructures which are successfully compared in terms of material quality to the standard HEMT heterostructures grown on bulk SiC substrates. Their electrical characteristics, such as sheet carrier density ( N s), mobility ( μ), pinch-off voltage ( V p) or sheet resistance ( R s), are very similar to those obtained on bulk SiC substrates and their crystallographic properties, assessed by high-resolution X-ray diffraction (HR-XRD), transmission electron microscopy (TEM) and atomic force microscopy (AFM), seem to be in good agreement with the above-mentioned electrical characteristics. First devices with 0.5 μm gate length, made on these specific composite wafers, exhibit very good microwave performances, with output power of 5 W/mm at 10 GHz, similar to those obtained on bulk SiC substrates, showing the promising capability of SiCopSiC composite substrates.